// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_
#define CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "content/browser/renderer_host/overscroll_controller.h"
#include "content/common/content_export.h"
#include "ui/gfx/geometry/rect.h"

namespace content {

// The delegate receives overscroll gesture updates from the controller and
// should perform appropriate actions.
class CONTENT_EXPORT OverscrollControllerDelegate {
public:
    OverscrollControllerDelegate() { }
    virtual ~OverscrollControllerDelegate() { }

    // Get the bounds of the view corresponding to the delegate. Overscroll-ending
    // events will only be processed if the visible bounds are non-empty.
    virtual gfx::Rect GetVisibleBounds() const = 0;

    // This is called for each update in the overscroll amount. Returns true if
    // the delegate consumed the event.
    virtual bool OnOverscrollUpdate(float delta_x, float delta_y) = 0;

    // This is called when the overscroll completes.
    virtual void OnOverscrollComplete(OverscrollMode overscroll_mode) = 0;

    // This is called when the direction of the overscroll changes.
    virtual void OnOverscrollModeChange(OverscrollMode old_mode,
        OverscrollMode new_mode)
        = 0;

private:
    DISALLOW_COPY_AND_ASSIGN(OverscrollControllerDelegate);
};

} // namespace content

#endif // CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_
